A database created by an older version of Neo4j will be upgraded when opened by
Neo4j 2.2.0-M04 during startup. Whilst this upgrade will occur
automatically for minor changes, larger migrations require explicit
configuration before Neo4j will start.

Each Neo4j version supports upgrading from a limited number of previous versions. These upgrades are either automatic, or require explicit configuration to allow them.

Downgrade is only supported between Neo4j versions that allow for automatic
store upgrades. This typically means only within patch releases of the same Neo4j
version.

Automatic Store Upgrade

To perform a normal store upgrade (for minor changes to the database store):

Cleanly shut down the older version of Neo4j, if it is running.

Install Neo4j 2.2.0-M04, and set it up to use the same database store directory (typically data/graph.db).

NOTE: It is strongly advised to make a copy of the database store directory at this time, to use as a backup in case rollback/downgrade is required. This is not necessary if a backup has been made using the online backup tool, available with Neo4j Enterprise.

Start up Neo4j.

Any database store upgrade required will occur during startup.

Explicit Store Upgrade

To perform an explicit store upgrade (required for significant changes to the
database store):

Cleanly shut down the older version of Neo4j, if it is running.

Install Neo4j 2.2.0-M04, and set it up to use the same database store directory (typically data/graph.db).

Set the Neo4j configuration parameter allow_store_upgrade=true in your conf/neo4j.properties file. Neo4j will fail to start without this configuration set.

Start up Neo4j.

The database store upgrade will occur during startup.

The allow_store_upgrade configuration parameter should be removed, set to false or commented out.

Information about the upgrade and a progress indicator are logged into the messages.log file, inside the database store directory.

Caution

An explicit upgrade will require substantial free disk space, as it must make an
entire copy of the database store. The upgraded store version may also require
larger store files overall. It is suggested to have available free disk space
equivalent to at least 1.5 times the size of the existing store.

Note

Cypher compatibility: The Cypher language is rapidly evolving, and may change
between Neo4j versions (although not between patch releases). However, Neo4j
supports compatibility directives for Cypher, that allow explicitly selecting a
language version. This is possible to do for individual statements, or
globally, as described in the Cypher Compatibility section.